1. Field of the Invention
The present invention relates to audio responsive devices, and more particularly to audio responsive color generators sometimes referred to as color organs.
2. Description of the Prior Art
Color generators or organs have been frequently used in the past either to provide entertainment or to serve as an advertising medium. In recent past the use of audio coupling has become quite prevalent and color organs coupled to sound are now easily found in the market place. Most frequently an audio transducer is used to provide the coupling, the organ including amplitude and frequency selection features which, by adjustment, are set to respond to the audio signal and to turn on lights. Typically devices of this kind operate on a threshold principle; the loudness of the received audio signal determining the setting of the light. The difficulty however, arises in the variations in loudness with each performance or song where in one instance the levels are constantly above the threshold, or alternatively, the threshold is never reached.
To overcome this problem variable gain controls have been utilized in the recent past which, according to the average signal, effectively vary the threshold. Gain control of this kind, however, also has some undesired features since it takes the same time constant to increase the gain as it takes for a decrease. Accordingly, as loudness changes within a song or performance, the response rate also changes.